Differential with shaft locking mechanism

Abstract

A shaft retention and spacer mechanism, referred to as a button lock assembly, is installed between the ends of the axle shafts within the differential housing of a differential assembly. The end of each axle shaft includes a button-like end pad formed by an annular groove that is adapted to receive a C-clip therein for axially locating and restraining a side gear between the differential housing and the axle shaft. The button lock assembly includes a spacer block having a peripheral flange extending outwardly from its opposite lateral face surfaces so as to define a pair of open-ended retention chambers. The spacer block is disposed between the axle shafts such that the button-like end pads are positioned within the retention chambers. The button lock assembly further includes a lock cap that is secured to the spacer block for enclosing the open end of the retention chambers to surround the end pads. Upon installation of the C-clip into the grooves, the end pads are retained in the retention chambers of the spacer block and the C-clips are laterally bounded by the side gear and the button lock assembly.

What is claimed is: 
     
       1. A differential comprising: a housing defining a chamber and a pair of aligned apertures;   a pair of output shafts having end segments extending through said aligned apertures in said housing and positioned in said chamber;   a gearset for transferring rotary power from said housing to said output shaft while permitting speed differential therebetween, said gearset retained in said chamber and including a pair of side gears fixed to said end segments of said output shafts; and   a button lock assembly including a spacer block disposed between said end segments of said output shafts and having peripheral flanges extending outwardly from its opposite lateral face surfaces to define open-ended retention chambers within which said end segments of said output shafts are retained, said button lock assembly further including a lock cap that is mounted to said spacer block to enclose said retention chambers for enclosing said end segments of said output shafts, and a fastener for securing said lock cap to said spacer block.   
     
     
       2. The differential of claim 1 wherein said end segments of said output shafts each include an annular groove and an end pad adapted to be retained in said retention chamber, and further comprising a retainer clip adapted for retention in said annular groove and against a corresponding one of said side gears for axially locating and restraining said side gear on said end segment of said output shaft between said retainer clip and said housing. 
     
     
       3. The differential of claim 2 wherein said retainer clip is adapted to be retained in an annular chamber formed in said side gear and which is alignable with said annular groove in said output shaft such that said retainer clip is laterally bounded by said side gear and said button lock assembly. 
     
     
       4. The differential of claim 2 wherein said end pad has an outer face surface adapted to be located in proximity to said lateral face surface of said spacer block and a peripheral surface adapted to be located in proximity to an inner edge surface of said peripheral flange. 
     
     
       5. The differential of claim 2 wherein said lock cap has a face surface adapted to be located in proximity to a mounting surface on said spacer block such that a lug extending from said face surface of said lock cap encloses said open end of said retention chamber. 
     
     
       6. The differential of claim 1 wherein said spacer block has a bore and said lock cap has an aperture alignable with said bore, and wherein said fastener extends through said aperture and into said bore to secure said lock cap to said spacer block. 
     
     
       7. The differential of claim 1 wherein said gearset further includes pinions rotatably mounted in gear pockets formed in said housing and which communicate with said chamber, said pinions including a first pinion meshed with one of said side gears and a second pinion meshed with the other of said side gears and said first pinion. 
     
     
       8. The differential of claim 7 wherein said gear pockets are parallel to a rotary axis of said output shafts. 
     
     
       9. A differential assembly comprising: a differential housing defining a chamber and a pair of aligned openings communicating with said chamber;   a pair of output shafts extending through said openings in said differential housing and having end segments located within said chamber;   a pair of side gears disposed in said chamber and fixed to said end segments of said output shafts;   paired sets of pinions rotatably mounted within said differential housing and in meshed engagement with each other and with one of said side gears; and   a button lock assembly including a spacer block having a body portion disposed between said end segments of said output shafts and retainer flanges extending from opposite sides of said body portion to partially surround said end segments of said output shafts, said button lock assembly further including a lock cap mounted to said body portion and extending beyond an edge of said body portion to define a cap flange which cooperates with said retainer flanges to completely surround said end segments and prevent said button lock assembly from moving laterally relative to said output shafts.   
     
     
       10. The differential assembly of claim 9 wherein said body portion of said spacer block includes a threaded bore for receiving a threaded fastener inserted through an aperture in said lock cap for securing said lock cap to said spacer block. 
     
     
       11. The differential assembly of claim 9 wherein said button lock assembly is free to rotate relative to said output shafts and said differential housing. 
     
     
       12. The differential assembly of claim 9 wherein said body portion and said retainer flanges of said spacer block are generally U-shaped to define a pair of open-ended retention chambers within which said end segments of said output shafts are located. 
     
     
       13. The differential assembly of claim 9 wherein said retainer flanges define a pair of open-end retention chambers within which said end segments of said output shafts are retained, and wherein said end segments of said output shafts each include an annular groove and an end pad adapted to be retained in said retention chamber, and further comprising a retainer clip adapted for retention in said annular groove and against a corresponding one of said side gears for axially locating and restraining said side gear on said end segment of said output shaft between said retainer clip and said housing. 
     
     
       14. The differential assembly of claim 13 wherein said retainer clip is adapted to be retained in an annular chamber formed in said side gear and which is alignable with said annular groove in said output shaft such that said retainer clip is laterally bounded by said side gear and said button lock assembly. 
     
     
       15. A differential assembly for supplying driving torque from a drive shaft to a pair of output shafts, comprising: a differential housing adapted to be rotatably driven by the drive shaft, said housing defining a chamber having shaft openings at opposite ends thereof;   a pair of side gears disposed in said chamber, said side gears being non-rotatably mounted to end segments of the output shafts which extend through said shaft openings;   a pair of meshed differential pinions rotatably mounted within gear pockets formed in said differential housing, said pinions having a longitudinal axis parallel to the axis of said side gears with each pinion meshed with one of said side gears; and   a button lock assembly including a spacer block having a body portion disposed between said end segments of the output shafts and a peripheral flange extending from opposite sides of said body portion which encloses an outer surface of said end segments of the output shafts, wherein said button lock assembly is free to rotate relative to the output shafts and said differential housing.   
     
     
       16. The differential assembly of claim 15 wherein said button lock assembly further includes a lock cap attached to said spacer block, said lock cap cooperating with said peripheral flange for securing said button lock assembly between said end segments of the output shafts. 
     
     
       17. The differential assembly of claim 15 wherein said peripheral flanges define a pair of open-end retention chambers within which said end segments of the output shafts are retained, and wherein said end segments of the output shafts each include an annular groove and an end pad adapted to be retained in said retention chamber, and further comprising a retainer clip adapted for retention in said annular groove and against a corresponding one of said side gears for axially locating and restraining said side gear on said end segment of the output shaft between said retainer clip and said housing. 
     
     
       18. The differential assembly of claim 17 wherein said retainer clip is adapted to be retained in an annular chamber formed in said side gear and which is alignable with said annular groove in the output shaft such that said retainer clip is laterally bounded by said side gear and said button lock assembly.